Chronic diarrhea overview
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Chronic diarrhea Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Omodamola Aje B.Sc, M.D. [2]
Overview
Chronic diarrhea is a common symptom of many conditions with an estimated prevalence of 5%. Although chronic diarrhea has multiple definitions, a current working definition is the production of loose stools for longer than 4 weeks’ duration. Frequent defecation with normal consistency is termed psuedodiarrhea. There are 3 basic categories of chronic diarrhea: watery, fatty(malabsorption) and inflammatory (with blood and pus). The fundamental pathophysiology of all diarrhea is altered intestinal water and electrolyte transport caused by several factors majorly dependent on the socio-economic status of the population. Treatment is targeted at treating the underlying cause of the diarrhea.
Historical Perspective
The word diarrhea derived from the Greek term "to flow through," is a common manifestation of gastrointestinal disease. Its definition has traditionally been based upon the frequency, volume, and consistency of stools. As a result of various inconsistencies in definition, the American Gastroenterological Association suggests that chronic diarrhea should be defined as a decrease in fecal consistency lasting for four or more weeks.
Classification
Chronic diarrhea may be classified into 3 basic categories: watery, fatty(malabsorption) and inflammatory (with blood and pus). It is important to note that not all chronic diarrhea falls into one category alone. Classifying the patient with chronic diarrhea into a subcategory helps to direct the diagnostic work-up.
Pathophysiology
The fundamental pathophysiology of all diarrhea is incomplete absorption of water from the lumen either because of a reduced rate of net water absorption (related to impaired electrolyte absorption or excessive electrolyte secretion) or because of osmotic retention of water intraluminally. Thus, diarrhea is a condition of altered intestinal water and electrolyte transport.
Causes
Depending on the socio economic status of the population, chronic diarrhea can be caused by several factors. In a developing nation, the most likely causes of chronic diarrhea are mycobacterial and parasitic infections and less likely to include functional disorders such as malabsorption and inflammatory bowel diseases. In a developed nation however, the most likely cause of diarrhea are irritable bowel syndrome (IBS), inflammatory bowel disease, malabsorption syndromes (such as lactose intolerance and celiac disease), and chronic infections (particularly in patients who are immunocompromised).
Differentiating Chronic Diarrhea from other Conditions
The differential diagnosis for chronic diarrhea is enormous, with a large number of diagnostic tests available that can be used to evaluate these patients. Classifying the patient with chronic diarrhea into a subcategory helps to direct the diagnostic work-up.
Epidemiology and Demographics
In developed countries, the prevalence of chronic diarrhea is estimated to be about 300-500/100,000 person.
Risk Factors
The risk factors of chronic diarrhea can be assessed based on the epidemiological associations and the patient characteristics .Some of theses factors can be classified based on travel history, epidemics and outbreaks, diabetic patients, patients with acquired immune deficiency syndrome and whether the patients are institutionalized or hospitalized.
Natural History, Complication and Prognosis
If left untreated, patients with chronic diarrhea may progress to develop symptoms of altered sensorium due to electrolyte imbalance, dehydration, and malnutrition. Common complications of chronic diarrhea include confusion, perforated bowels, sepsis and death. Prognosis is generally good when the underlying cause is identified and treated early.
Diagnosis
There are no criteria for the diagnosis of chronic diarrhea. However, in order to make an accurate diagnosis, it is important to be able to take a detailed history, physical exam and mostly from expert opinion and from experience in individual clinical centers. The use of these methods are subject to bias however, a specific diagnosis can be achieved in more than 90% of patients.
History and Symptoms
Obtaining the history is the most important aspect of making a diagnosis of chronic diarrhea. Specific histories about the symptoms (duration, onset, progression), associated symptoms, drug usage have to be obtained. The hallmark of chronic diarrhea is loose stools lasting for 4 weeks or more. A positive history of foul smelling stools that are difficult to flush, bloody loose bowel movement, and crampy abdominal pain are suggestive of chronic diarrhea. The most common symptoms of chronic diarrhea include crampy abdominal pain, elevation in body temperature, and increased frequency of bowel movemnets.
Physical Examination
Some of the physical findings of chronic diarrhea are orthostatic hypotension, dehydration, neuropathy, muscle wasting, edema, malnutrition, urticaria pigmentosa, dermatographism, pinch purpura, macroglossia, hyperpigmentation, addison’s disease, migratory necrotizing erythema
Laboratory Findings
The laboratory findings in chronic diarrhea include complete blood count to evaluate for anemia, abnormal white blood cell count, electrolytes, thyroid tests, serological tests for celiac disease and stool analysis for fecal leukocytes, fecal lactoferrin, fecal occult blood. Some other diagnostic studies that have been adopted in the diagnosis of chronic diarrhea include flexible sigmoidoscopy, colonoscopy, esophagogastroduodenoscopy and capsule endoscopy.
Electrocardiogram
There are no electrocardiogram findings associated with chronic diarrhea.
Chest X Ray
There are no chest X Ray findings associated with chronic diarrhea.
CT Scan
There are no CT findings associated with chronic diarrhea.
Other Imaging Findings
There are no additional imaging findings for chronic diarrhea.
Treatment
Medical Therapy
Medications are the mainstay of treatment, the treatment of chronic diarrhea is targeted at treating the underlying cause. Antidiarrheal drugs are mainly employyed for symptomatic treatment which acts by improving stool consistency, reducing stool frequency, or reducing stool weight.[1]
Surgery
Surgical intervention is not usually recommended for the management of chronic diarrhea. However, depending on the underlying cause, surgery may be required.
Prevention
There is no established method for the prevention of chronic diarrhea. There are no vaccines for the prevention of the disease. However, depending on the underlying cause, hand washing and other sanitary processes can be adopted.
References
- ↑ Schiller LR (1995). "Review article: anti-diarrhoeal pharmacology and therapeutics". Aliment Pharmacol Ther. 9 (2): 87–106. PMID 7605866.